Electrodeposition of platinum and silver into chemically-modified microporous silicon electrodes.

Electrodeposition of platinum and silver into hydrophobic and hydrophilic microporous silicon layers was investigated using chemically-modified microporous silicon electrodes. Hydrophobic microporous silicon enhanced the electrodeposition of platinum in the porous layer. Meanwhile hydrophilic one showed that platinum was hardly deposited within the porous layer and a filmy growth of platinum on the top of the porous layer was observed. On the other hand, the electrodeposition of silver showed similar deposition behavior between these two chemically-modified electrodes. It was also found that the electrodeposition of silver started at the pore opening and grew toward the pore bottom, while a uniform deposition from the pore bottom was observed in platinum electrodeposition. These electrodeposition behaviors are explained on the basis of the both effect, the difference in overpotential for metal deposition on silicon and on the deposited metal, and displacement deposition rate of metal.